The role of multimodal navigation in endoscopic endonasal surgery for giant pituitary adenomas

Background: Giant pituitary adenoma (GPA) (diameter >40 mm) remains challenging to treat, and the radical resection rate is low. The intraoperative multimodal navigation is sometimes used in endoscopic endonasal surgery (EES). However, the effect of this technique on GPA surgical outcomes is not clear. This study aims to explore the surgical and clinical outcomes of the navigation used in EES for GPA. Methods: A retrospective review of 60 consecutive patients with GPA who underwent EES was performed. The total resection rate, residual volume, clinical outcomes, and complications were compared. Factors associated with tumor gross total resection (GTR) were analyzed by multinomial logistic regression analysis. Results: There were 31 patients in the standard group in which intraoperative multimodal navigation was not used, with a mean maximum tumor diameter of 5.21 +/- 1.24 cm; meanwhile, there were 29 patients in the navigation group, in which navigation was used, with a mean maximum tumor diameter of 5.32 +/- 1.18 cm. GTR was achieved in 10 patients (32.26%) in the standard group, which was significantly lower than that in the navigation group (18/29=62.07%). The residual volume was 7.93 +/- 10.78 cm(3) in the standard group which was significantly greater than that in the navigation group (2.44 +/- 1.26 cm(3), P=0.046). There was no significant difference between the two groups in terms of cerebrospinal fluid (CSF) leak, new pituitary deficit, and postoperative diabetes insipidus (DI). The higher Knosp grade of tumor, lobulated configuration and lack of intraoperative multimodal navigation use were relative risk factors associated with the GTR. Conclusions: The intraoperative multimode navigation appeared to be safe and effective when used in EES for GPA with higher GTR and lower residual tumor volume.